(Updated: October 1998)
The dissolution of the communist system in Eastern Europe proved to be a watershed for Yugoslavia, encouraging nationalist sentiments in its republics and laying the groundwork for the election of several separatist-minded governments by 1990. In June 1991, Slovenia and Croatia declared their independence, while the parliament of Bosnia and Herzegovina adopted a declaration of sovereignty a few months later.

The moves alarmed ethnic Serbs in those regions, whose centuries-old hatreds and suspicions against the various groups ran deep. After the breakout of a brief conflict in Slovenia, and the start of a protracted fight in Croatia between the Croatian nationalists and Yugoslavia  which vowed to support ethnic Serbs in the various regions  the civil war spread to Bosnia.

In hindsight, Bosnia's descent into war seemed almost unavoidable. By 1991, Bosnian Serbs had become increasingly agitated over the majority Muslim government's separatist moves, threatening violence if the republic did not remain part of the Serbian-dominated Yugoslav federation. Meanwhile, fighting from Croatia had already begun to spread over the border into Bosnia as of early 1992.

In March 1992, Bosnian voters overwhelmingly approved independence in a national referendum  a vote boycotted by the minority Bosnian Serbs, who almost immediately began a series of attacks on Muslim towns with the backing of the Yugoslav military. By the end of the spring of 1992, Bosnian Serbs, who had significant superiority in weaponry, took control of more than 60 percent of Bosnia's territory.

In April 1992, the European Community recognized Bosnia as an independent state, as did the United States. Days later, the Bosnian Serbs declared their own republic within Bosnia, headquartered in Pale, near the Bosnian capital, Sarajevo.

The ensuing three-year war between the Muslims, Bosnian Croats and the Bosnian Serbs would prove to be one of the most brutal conflicts in recent memory. Rape, robbery, and mass murder of civilians, part of a Serb strategy of "ethnic cleansing" in certain areas, would characterize much of the conflict during the period. (Note: The Muslims did initiate their own form of "ethnic cleansing," but to a far lesser degree.)

Bosnian Muslim and Croat losses early in the war reflected another of the conflict's complicated realities: In addition to fighting the Serbs, the two sides were also fighting each other in 1992 and 1993  much of that involving disputes over who would control particular territories once the Serbs were defeated. By summer 1992, Serb militias had wrested control of 70 percent of Bosnia, with the Muslims and Croats holding the rest.

During the summer of 1992, the United Nations attempted to stem the conflict's reach, sending peacekeepers into Sarajevo and other towns to facilitate the delivery of humanitarian relief. The efforts, however, met with much resistance as Serb gunners fired on U.N. convoys, periodically stopping relief from reaching the needy. To help insure the safety of its operations, the U.N. imposed a no-fly zone over Bosnia in October 1992, which NATO forces began to enforce in 1993.

As the conflict widened and the shelling of Sarajevo worsened, the U.N. moved to declare the capital and five other Muslim enclaves  Tuzla, Srebrenica, Gorazde, Bihac, and Zepa  "safe areas" under U.N. protection in April 1993. In August, NATO announced its willingness to protect these areas in coordination with the U.N.  a move that temporarily ended the siege of Sarajevo, but did little to stop the shelling in the other declared zones.

Criticism of the U.N. and the United States subsequently grew stronger by 1993, as the moves failed to stop Serb aggression. In particular, with Muslims already at a disadvantage in terms of weaponry, the U.N. came under fire for failing to repeal its arms embargo on the warring parties  a prohibition that critics said left Muslims unable to defend themselves.

In February 1994, peace efforts received another setback when a Bosnian Serb mortar shell landed in a crowded, open-air market in Sarajevo, killing 68 and wounding more than 200  an attack that would prove to be the bloodiest in the three-year siege of the capital. In response, NATO issued an ultimatum threatening to bomb Bosnian Serb positions if they did not withdraw from U.N. exclusion zones around Sarajevo.

The Serb offensives on the several fronts, combined with U.S. mediation efforts, helped to produce a March 1994 agreement between the Muslim-led Bosnian government, the Bosnian Croats, and the government of Croatia, establishing a Muslim-Croat confederation in Bosnia. Fighting between the Croats and Muslims effectively ceased as the two sides turned their attention to Serb forces.

As the year wore on, NATO also began focusing its efforts on Bosnian Serb forces, initiating April 1994 air strikes against the group for their siege of Gorazde, then later in 1994, expanding the strike range to include the area of Bihac, where Bosnian and Krajina Serbs (from Croatia) had become involved in new fighting.

A brief cease-fire between the Muslim-Croat Federation and the Bosnian Serbs was negotiated in December 1994, with both sides agreeing to a cessation of hostilities for four months. When the period expired, however, hostilities erupted anew as Bosnian Serb forces renewed attacks on Sarajevo and Srebrenica. By July 1995, the U.N.-declared safe areas of Srebrenica and Zepa fell to Serb forces. As attacks on the areas continued, NATO began an intensive month-long bombing campaign against Bosnian Serb forces.

Dead and wounded lie outside a Sarajevo market in August 1995 after a mortar shell exploded outside the entrance of the building. (File)

Despite the fall of the two safe areas, Muslim fighters, along with Croatian militias and soldiers from Croatia, by summer 1995, began to retake several areas Serbs had captured from them at the beginning of the war  eventually controlling about half the country by autumn. Those gains combined with NATO bombings helped to provide the basis for diplomatic efforts to end the crisis.

At September 1995 meetings sponsored by Russia, the United States, Britain, France, and Germany  known as the Contact Group  the foreign ministers of Bosnia, Croatia, and Serbia (representing the Bosnian Serbs) agreed to the basic principles for a peace settlement. That included the preservation of Bosnia as a single state, and an equitable division of territory between the Muslim-Croat Federation and the Bosnian Serbs.

After a negotiated October 1995 cease-fire, the Contact Group and warring parties met in November in Dayton, Ohio, to begin the peace process. On November 21, the parties agreed to a settlement, effectively creating two autonomous entities in the country: the Federation of Bosnia and the Bosnian Serb Republic.

In September 1996, voters went to the polls and elected Muslim Alija Izetbegovic chairman of the country's three-person collective presidency, with a Croat and a Serb serving as its other members. Two years later, voters would elect hard-line nationalist Nikola Poplasen as the Bosnian Serb Republic's president, replacing a more moderate, Western-backed leader, Biljana Plavsic. The victory of Poplasen  who had previously expressed his opposition to the Dayton accord  dealt a huge blow to U.S. officials and others who hoped to rebuild Bosnia into a multiethnic regime.

Bosnia remains the only former Yugoslav republic with a Muslim plurality, about 44 percent, while 31 percent are Serbs and 17 percent are Croats.
 Tim Ito, Washingtonpost.Newsweek Interactive producer